Study On Electric Network Structure Schedule To Support Source&Load Power Balance

In order to develop the modern economic system with high quality,energy reform and promote clean new energy are necessary.At present stage,the proportion of renewable energy generation power generation and the structure of energy utilization continuously increase,e.g.In Shandong,15%of the daily energy consumption is new energy.In addition,the controllable and interruptible of active load and complexity of power source,electric network and load are speedily add up.Thus,there are more challenges in front of the dispatch and control of power system.Under this circumstance,the voltage support capability and the power transmission capability become a serious problem.The contradictions between power sources and consumption are more intractable.In addition,maintaining the voltage support capability and power transmission capability challenge the operation of power system.The limitation of economic dispatch under the fixed electric network structure has gradually emerged.Mine the flexibility of existing electric network is necessary to support power balance of source and load,so that the synergistic capability of power source,electric network and load can be greatly enhanced.In this paper,we apply the optimal electric network structure to cope with the balance between power source and load.Following shows the three research questions we answered in this paper.First,we explain the significance of optimal electric network structure on the basis of the 'non-coherence situation'.The model of economic dispatch considering electric network structure is proposed under DC OPF and AC OPF individually.In order to explore the influence of reactive voltage on the accuracy and feasibility of optimization results,we use a test system which compares the decision effect of traditional economic dispatch and the proposed model.Second,considering optimal electric network structure,we develop an algorithm of decomposition-coordination economic dispatch for the interconnected power grid.Because of the interconnected power grid formed by multi-area power grids,we copy the border bus so that the whole grid can be divided into regional grids which relatively independent and coupling with each other.As a result,we simultaneously and independently optimize the network structure and made the decision for regional economic dispatch.ADMM algorithm is applied to coordinate adjacent regions to realize synergy of interconnected power grid and economy of the whole system.Finally,higher requests have been brought forward on the system's reactive voltage regulation capability to support the balance of source and load.We propose the economic dispatch model with electric network structure optimization,which considering the reactive voltage regulation characteristics of renewable energy.Therefore,we analyze voltage characteristics of wind power and photovoltaic generation system.Then formulate the mathematical model of optimal electric network structure based on AC OPF for power system with wind and photovoltaic generation.This paper proposed a combination of genetic algorithm and the nonlinear primal-dual interior point method.The test results show that our method benefits to the flexibility and economy of power system operation,also the accommodation of renewable generation.